Table 1. Electrolytes and glucose renal handling and characteristics of nondiabetic patients by CKD stages in the cross-sectional study.
| Variables | All patients | Non-CKD | CKD |
P value | |||
|---|---|---|---|---|---|---|---|
| Stage 1 & 2 | Stage 3 | Stage 4 | Stage 5 | ||||
| Patients, n | 208 | 63 | 23 | 58 | 32 | 32 | |
| Demographic data | |||||||
| Age, mean (SD), y | 57 (15.2) | 53.5 (13.4) | 45.8 (18.8) | 60.1 (13.5) | 62.9 (14.8) | 60.4 (14.2) | <0.001 |
| Male, n (%) | 74 (35.6) | 6 (26.1) | 28 (44.4) | 18 (31) | 12 (37.5) | 10 (31.3) | 0.007 |
| SBP, mean (SD), mmHg | 129.8 (17.1) | 126.7 (15) | 123.4 (14.5) | 127.8 (17.7) | 129.9 (14.6) | 144.0 (17.2) | <0.001 |
| eGFR, mean (SD), ml/min/1.73 m2 a | 52.5 (33.8) | 83.5 (17.3) | 92.4 (30) | 43.8 (8.4) | 21.6 (3.7) | 9.6 (9.2) | <0.001 |
| Urine PCR, median (IQR), mg/g | 201 (87–1323) | 80 (51–114) | 772 (641–1278) | 127 (84–617) | 1043 (283–1496) | 1814 (1400–4745) | <0.001 |
| Renal tubular function | |||||||
| FE glucose, median (IQR), % | 0.1 (0.1–0.4) | 0.1 (0.1–0.1) | 0.1 (0.1–0.2) | 0.1 (0.1–0.2) | 0.3 (0.2–0.7) | 6.8 (1.8–25.2) | <0.001 |
| FE Na, median (IQR), % | 0.7 (0.4–1.9) | 0.5 (0.3–0.6) | 0.4 (0.2–1.1) | 0.7 (0.5–1.2) | 1.9 (1.7–2.1) | 3.6 (2.9–6.6) | <0.001 |
| FE K, median (IQR), % | 13.1 (8.4–22.9) | 8.4 (6.3–12.0) | 10.0 (6.3–28.4) | 12.8 (9.9–15.8) | 19.4 (13.5–26.6) | 44.2 (28.1–93.2) | <0.001 |
| FE UA, median (IQR), % | 7.8 (5.2–14.9) | 5.7 (3.8–8.5) | 7.4 (3.5–11.7) | 7.3 (4.5–9.4) | 15.0 (6.2–19.0) | 36.2 (21.6–45.6) | <0.001 |
| Glycosuria by dipstick, n (%) | 22 (10.6) | 0 | 0 | 2 (3.4) | 2 (6.3) | 18 (56.3) | <0.001 |
| FE glucose >1%, n (%) | 36 (17.3) | 1 (1.6) | 2 (8.7) | 2 (3.4) | 4 (12.5) | 27 (84.4) | <0.001 |
| FE glucose >4%, n (%) | 25 (12.0) | 1 (1.6) | 0 | 2 (3.4) | 2 (6.3) | 20 (62.5) | <0.001 |
| Urine NGAL-to-creatinine (ng/mg) | 0.01 (0.00–0.01) | 0.03 (0.01–0.05) | 0.11 (0.52–0.23) | 0.24 (0.14–0.50) | 1.16 (0.17–2.43) | 13.84 (3.64–30.94) | <0.001 |
| Biochemistry and electrolytes | |||||||
| Blood glucose, mean (SD), mg/dL | 101.1 (18) | 100.1 (15.3) | 97.2 (18.2) | 101.5 (13.0) | 104.4 (26.7) | 102.1 (20.0) | <0.001 |
| Sodium, mean (SD), mEq/L | 139.2 (4.1) | 139.2 (4.1) | 139.3 (4.1) | 139.8 (4.0) | 138.1 (4.3) | 139.2 (4.3) | 0.002 |
| Potassium, mean (SD), mEq/L | 4.1 (0.7) | 3.9 (0.3) | 3.8 (0.8) | 4.1 (0.5) | 4.4 (1.0) | 4.7 (0.7) | <0.001 |
| Calcium, mean (SD), mg/dL | 9.0 (0.8) | 9.2 (0.9) | 9.0 (0.6) | 9.2 (0.8) | 8.9 (0.6) | 8.4 (0.5) | <0.001 |
| Phosphorus, mean (SD), mg/dL | 4.1 (1.5) | 3.6 (1.9) | 3.9 (0.8) | 4.0 (1.4) | 4.3 (1.5) | 4.9 (1.1) | <0.001 |
| Uric acid, mean (SD), mg/dL | 7.2 (1.8) | 6.4 (1.5) | 7.1 (1.6) | 7.6 (1.9) | 7.9 (2.0) | 7.8 (1.5) | <0.001 |
Abbreviations: CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; FE glucose, fraction excretion of glucose; FE K, fraction excretion of potassium; FE Na, fraction excretion of sodium; FE UA, fraction excretion of uric acid; Hba1c, glycosylated hemoglobin; IQR, interquartile range; NGAL, neutrophil gelatinase-associated lipocalin; SBP, systolic blood pressure; SD, standard deviation; UPCR, urine protein-creatinine ratio.
P < 0.05 indicates a significant difference among groups by ANOVA.
aObtained by using the Modification of Diet in Renal Disease study equation.